Conventional systems are the older type of fire alarm systems.The detector communicates with the fire alarm control panel simply by changing state from high impedance to low impedance when smoke is detected.Smoke detectors are typically wired together up to 32 detectors on each zone and a single fire alarm control panel can usually monitor a number of zones which can be arranged to correspond to different areas of a building.In the event of a fire, the fire alarm control panel is able to identify which zone contains the detector or detectors in alarm, but it�s not able to identify which individual detector or detectors is in an alarm state.